Door mechanism



Oct. 27, 1964 1 T. cAvALLERo ETAL 3,154,303

nooR MECHANISM Filed Jan. 8, 1962 3 Sheets-Sheet 1 ATTOR NE YS Oct 27, 1964 1..-r. cAvALLERo r-:TAL 3,154,303

DOOR MECHANISM 3 Sheets-Sheet 2 Filed Jan. 8, 1952 Oct 27, 1964 T. cAvALLERo ETAL 3,154,303

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United States Patent O 3,154,303 DOOR l'vIECHANISM Louis T. Cavallero, Hamilton, Robert R. McKellar, Kettering, and James L. Walker, Hamilton, Ohio, assignors to The Black Clawson Company, Hamilton, Ohio, a

corporation of Ohio Filed Jan. 8, 1962, Ser. No. 164,852 6 Claims. (Cl. 268-58) The present invention relates to an automatically opened door and particularly to a highly sensitive failsafe door system.

Many continuous processes require that the ambient environmental conditions surrounding the process machinery be strictly controlled in order to achieve maximum efficiency and the highest possible quality in the resulting product. In an elort to control these ambient conditions, enclosures or hoods have been proposed which will entirely enclose the machinery and provide a well dened space around the machinery in which the air temperature, humidity, and rate of tlow can be accurately regulated. The prime disadvantage of such an enclosure is that it isolates the machinery so that maintenance and repair thereof may be quite difficult. The problem is especially acute in high speed processing machinery, such as paper coaters and driers, when the web of paper breaks thereby necessitating immediate access to the machinery so that the rapidly accumulating broke can be removed and the web again threaded through the machinery. The access must be such that every point along the machinery can be reached immediately and without requiring the attending personnel to dodge the supports, panels, or other obstructions that hamper their primary function of obviating the trouble in the processing machinery.

A solution to the problem is the use of doors which move upwardly to open an aperture thereby allowing workmen to gain access to the machinery. Such a door system must be highly reliable and capable of immediately opening an aperture as much as 7 to 10 feet high along the base of the hood in response to actuation of a simple manual switch so that no time is lost in attending the machinery. In addition, for obvious reasons of safety, the aperture must be free from any obstruction and the door must be locked into the raised position so that it does not unexpectedly fall. Similarly, it is desirable to have safety apparatus which will automatically terminate the lowering of the door when it contacts an object as it passes thereby obviating possible personnel injuries or damage to the door system.

Accordingly, a particular object of the invention is to provide an improved door operating mechanism for automatically raising and lowering a door to open and close an opening in an enclosure.

Another object of the invention is to provide an improved door operating mechanism including guiding apparatus therefor which restricts the movement of the door to a predetermined path without, in any way, obstructing the aperture which is opened and closed by the door.

A further object of this invention is to provide a door mechanism for covering an access opening in an enclosed machinery hood wherein the door cannot unexpectedly move toward the lowered or closed position due to power failure or other malfunctions of the door actuating mechanism, as well as apparatus to terminate movement of the door when the lower edge thereof contacts any obstruction or object thereby providing a door which will not endanger persons who are attending the machinery enclosed by the aforesaid hood.

A still further object of this invention is the provision ICC of a door operating mechanism having a manually initiated cycle which includes the commencement of the operation of a fluid pump, the distribution of the pressured fluid generated by the pump to the fluid motor which moves the door, and the starting of apparatus which maintains the operation of the cycle for a predetermined time interval subsequent to the initiation of the cycle.

Other objects and advantages of the invention will be apparent from the following description and the appended claims.

In the drawing FIG. 1 is a side view of an enclosure embodying the invention;

FIG. 2 is a sectional view essentially along the line 2-2 of FIG. 1;

FIG. 3 is a sectional view similar to that of FIG. 2 and taken essentially along the line 3-3 of FIG. l;

FIG 4 is a cross-sectional view along the line 4-4 of FlG. 3;

FlG. 5 is a cross-sectional view essentially along the line 5 5 of FlG. 4;

FIG. 6 is a partial side view of the door ,assembly as viewed from the inside of the enclosure;

FIG. 7 is a view showing the mounting fixtures for the iluid actuator;

FlG. 8 is a sectional view essentially along the line 8 3 of FIG. 6;

FlG. 9 is a diagrammatic illustration of the hydraulic circuitry of the invention;

PEG. l0 is a cross-sectional View of the holding valve utilized with the hydraulic control system; and

FIG. l1 is a diagrammatic illustration of the electrical sub-system.

Referring to the drawings, which illustrate a preferred embodiment of the invention, FIG. 1 illustrates a hood 1t) which encloses processing machinery 11, for example, high :speed paper drying apparatus, which requires that the temperature, humidity and rate of ilow of the ambient air be accurately regulated to obtain the maximum eiliciency of the process. The hood lil includes a roof section 12 having a side wall 13 coextensive therewith and extending from the roof downwardly to a point short of the floor to provide an unobstructed opening 14 to the process machinery so that access may be gained thereto should the web break or other diiculties arise which require immediate access to the machinery.

To close this opening 14, a series of vertically movable doors 15 are provided so that when trouble develops, they can be automatically raised to permit unobstructed access to the entire length of the machine. As shown in FlGS. 2-5, the doors are supported and movable on guide rods 17 mounted at either side of each door 15 and extending from near the roof 12 downwardly to the lower edge of the side wall 13. Rods 17 are mounted on vertical guiderod supports 18 which are coextensive therewith and secured to the roof support members 19. If desired, the lower portion of the guide rod support 18 may be connected to the machinery for additional support.

As shown in FIGS. 4-6, arms 20 extend upwardly from the side of each door 15. A guide bushing 21 is mounted at either end of each of these arms 20, each having a bearing member 23 mounted therein (see FIG. 5) which rides on its associated rod 17 so that the movement of the door is restricted and controlled by these guide rods 17. A rubber member 24 resiliently mounts the bearing member 23 within the bushing 21 so that the latter will ride easily on the guide rod 17. Arms 20 permit the entire guide assembly to be raised 'above the lower edge of the side 4wall 13 without requiring guide means which extend into or otherwise obstruct the opening 14. While this guide means is preferred it is contemplated that others may be utilized, for example, a rail withV shoes riding thereon.

A hydraulic cylinder 25 automatically raises and lowers each door 15 in response to activation of a control system (to be described hereinafter. As shown in FIGS. 6 and 7,

the upper end of the cylinder 25 has a U-shaped member 27 secured thereto with a hole 28 therethrough. When the lug 30 on the cross member 31 which has a similar aperture 33 therethrough is interleaved with the member 27 and pin 34 inserted therethrough, the cylinder 25 is securely mounted in an operative position since the cross member 31 is rigidly secured to the roof support members 19. Similarly, the output shaft 38 of the cylinder 25 is secured by a pin 39 to the U-shaped member 4t) on the cross member 41 which extends between the vertical struts 43 of the door 15. The stroke of the cylinder 25 is suiiicient to move the door 15 between a raised position, wherein unobstructed access is provided to the machinery as Shown on theleft side of FIG. l, and a lowered or closed position, wherein the door 15 completely closes and seals the opening 14, as `shown by the door on the right side of FIG. l.

Along the entire length of the lower edge of each door is a safety sensing mechanism 44 (see FIG. 8) which is operably connected to the control system for terminating the movement of the door 15 in response to contact by this edge with any object blocking its path. The mechanism 44 includes a lower member 4S which is shown as Aa strip of wood attached to the metal channel 46 which forms the lower edge of the door 15. The wooden strip 45 is secured between straps 48 by screws 49, and it has three members t), 51 and 52 of foam rubber or soft exiblermaterial bonded thereto as shown. The outside members 51 and 52 extend downwardly a greater extent than the central member 5i) and have a fourth flexible strip 55 bonded thereto to form a chamber 58.

A contact strip 6i) .of material which will readily conduct electric current, e.g., copper, is bonded to each of the members 50 and 55. Enclosing the entire safety mechanism 44 including the ends thereof and secured to the channel 46 by screws 62 isa protective boot 63 composed of neoprene or other exible and durable material to protect but not interfere with the operation of the safety mechanism. While only a single cross section of this edge assembly has been shown, it should be understood that it is coextensive with the lower channel 46 of each door Y15. The leads 64 which extend from and are connected to each of the contact strips 66 tie the same into the control system as identified hereinafter in connection rwith FIG. 1l. The manner in which leads 64 extend through the mechanism 44 can be varied without departing from the scope of the invention. For example, they could extend vertically through members 50, 45, and 46.

The hydraulic portion of the control system, shown diagrammatically in FIG. 9, has a source of fluid pressure including a pump 65 driven by motor 66 and connected to a fluid reservoir 67 by conduit 68. Valve 70 effects the activation of the cylinder 25 by controlling the ow o f the pressurized iuid thereto and is normally mamtamed in a neutral or blocking position by springs `72 mounted on either side thereof so that fluid flow through the Valve is blocked. Solenoid 73 mounted on one side of the valve 70 is operable to move the valve 70 downwardly to a irst position wherein passage 75 interconnects the conduits 76 and 77 while the passage 78 interconnects the conduits 80 and 81. Movement of the 'valve in the opposite direction to the raised position is acby conduit 89. A control line Y conducts fluid from the conduit 77 to the holding valve 87.

A suitable construction for the holding valve 87 is shown in FIG. 10 and includes a body member 95 having the three lluid conduits 81, 89, and 90 connected thereto as shown in FIGS. 9-10. When pressurized fluid enters the passage 96 from conduit 81, it immediately overcomes the bias of the spring 98 on the ball valve 100 to open the orices 101 and permit flow through the central passage 103 to the conduit 89. However, when this directional ow is reversed, the ball valve will block any ow through the oriiice 101, and an increase in the uid pressure will merely increase the seating pressure of the ball valve 100.

Further as to valve 87, when the conduit 77 leading to the upper chamber 85 of cylinder 25 is pressurized, fluid ows through line 9i), passage 165, the orifice 107 and into the chamber 108 to force the poppet valve 110 to the right, as viewed in FIG. 10, against the bias of control spring 111, thereby permitting fluid ow from passage 103 through the openings 114, around the open poppet valve 110, and into they passageway 96. Hence flow in one direction is not materially affected by the holding valve 87 while ow in the opposite direction is dependent on the pressure in line 90. The amount of pressure required to open the poppet valve 110 can be adjusted, as desired, by loosening the lock nuts and adjusting the bolt 116 to vary the preloading on the control spring 111.

The electrical portion of the control system shown schematically in FIG. ll includes a power supply having mounted in series therewith a conventional fuse 122 which will protect the circuitry and association apparatus from damage in event of a short circuit of overloading thereof. Also mounted in series with the power supply 120 is the normally closed switch 125 which is opened by actuation of the solenoid 126 in response to completion of its circuit which occurs when the contact strips 60 of the safety edge 44 contact each other as the lower edge of the door 15 strikes an obstruction thereby interconnecting the leads 64. A separate power supply 127 is shown for this circuit but it should be understood that power supply 120 could also be vutilized with the circuit without departing 'from the invention.

Mounted in parallel withreach other and in series with the power supply 120 are two control relays 130 and 131 which initiate the door raising or lowering cycles, respectively. Two single throw double pole switches 133 and 134 are spring biased to the position shown in FIG. l1. Switch 133 includes contacts 136 and 137 which are utilized to make or break the energizing circuits for the relays and 131, respectively, and the switch 134 includes contacts and 141 which also make or break these energizing circuits, respectively. By-pass conductors 143 and 144 have therein normally open relay contacts 130e and 131e` mounted in parallel with the contacts 136 and 140, respectively. In addition, a manual Stop switch 147 is mounted in series with the relays 130431 for terminating actuation of the relays at any time.

Three pairs of normally open contacts 130a-c are closed by actuation of relay 130 whereas the similar contacts 131a-c are closed by relay 131. Contacts 13011 control the energizing circuit for the valve solenoid 74, while the contacts 131a similarly control the valve solenoid 73. The relay contacts 130b and 131b are connected in parallel in the energizing circuit for the pump motor 66. The normally closed contacts 145a and 146a are controlled by the timing relays 145 and 146, respectively.

In operation, when the door 15 is in the raised or in the lowered position and the control system is inoperative, the pump 65 is inactive and the four-way valve 70 is positioned by springs 72 in the neutral position wherein any ow to or from the hydraulic cylinder 25 is blocked. In addition, if the door 15 is in the raised position, the holding valve 87 blocks any ow from the lower chamber 88 of the cylinder 25 so that the door 15 cannot unexpectedly Vsaid fluid motor includes a cylinder having a piston `defining therein iirst and second pressure chambers, said valve means controlling the ow of said pressurized uid to and from said chambers so that said door is raised when said Huid is communicated to said first chamber and Ylowered when said uid is communicated to said second chamber, and a holding valve operably mounted between said valve means and said rst chamber to block flow from said lirst chamber except when pressurized uid is conducted to said second chamber.

3. A door operating mechanism for controlling the movement of a door between a raised and a lowered position including a uid motor connected thereto to effect Said movements, pump means for generating a pressurized uid, valve means for controlling the liow of said pressurized uidto said motor, control relay means, manually actuated switch means biased to an open position and operable when closed to actuate said control relay means, means for operating said pump in response to actuation yof said control relay means, means for positioning said valve means to conduct said pressurized uid to said motor in response to actuation of said control relay means to effect movement of Vsaid door toward either of said positions, a timer relay actuated by said control relay means, a timer switch mounted in a circuit in series with said manual switch means and actuated by said timer relay to maintain a circuit to said control relay means when said manual switch'is released, said timer relay being operable after the expiration of a predetermined amount of time to open said timer switch to inactivate said control relay means, and means mounted in series'with said control relay means to inactivate said relays when said door contacts an obstruction as it moves from said open position to said closed position.

4. A door operating mechanism for selectively controlling the movement of a door between a raised and a lowered position including a fluid motor for moving said door between said positions, a source of pressurized fluid, a valve for controlling the tlow of said pressurized fluid to and from said motor, means normally positioning said valve in a blocking position wherein ow of said pressurized uid to said motor is blocked, means for selectively moving said valve to a rst position wherein pressurized iluid is supplied to said motor to move said door to said raised position and for moving said valve to a second position wherein pressurized iiuid is supplied to said motor to move said door to said lowered position, timing means operable to effect the movement of said valve to said blocking position after the elapse of a ypredetermined amount of time subsequent to movement of said valve to either said rst or second position, and safety means for effecting movement of said valve to said blocking position in response to contact by said door with an object tending to block movement thereof toward said lowered position.

5. A fail-safe door operating system for selectively moving a door between a raised position and a lowered position including a iluid motor connected to said door; a pump for generating a pressurized uid; a fluid motor having a cylinder; a piston in said cylinder connected to said door and dividing said cylinder into an upper and a lower chamber; a valve for controlling the ow of said pressurized uid to and from said chambers; means normally positioning said valve in a neutral position; valve actuator means for positioning said valve in a raised position wherein the uid is conducted to said lower chamber to raise said door or in a lowering position wherein uid is conducted to said upper chamber to lower said door; control relay means for actuating said pump, for selectively operating said actuator means to position said valve in said raising or said lowering position, and for actuating a timer relay; manually actuated switch means biased to an open position and operable when actuated to energize said control relay means; a timer switch mounted in series with said switch means and closed by actuation of said timer relay, said timer relay being operable after the expiration of a predetermined time to open said timer switch; holding valve means for preventing flow of fluid from said lower chamber except in response to flow of pressurized fluid to said upper chamber; and means responsive to contact by the lower edge of said door with an obstruction to inactivate said control relay means.

6. A control system for selectively controlling the actuation of a iiuid motor having a cylinder divided into rst and second actuation chambers by a piston, including a source of pressurized uid, a valve for controlling the flow of pressurized liuid to said chambers, means for positioning said valve in a neutral position for blocking ylluid ow to and from said chambers, irst electrically actuated means for positioning said valve in a first position wherein said pressurized uid is conducted to said rst chamber, second electrically actuated means for positioning said valve in a second position wherein said pressurized fluid is conducted to said second chamber, Va rst control relay for actuating said iirst electrically actuated means, a iirst normally closed timer relay in series Vwith said first control relay for terminating operation thereof a predetermined time after actuation of said first control relay, a first manually actuated switch biased to an open position for actuating said rst control relay, a first switch mounted in parallel with said first manual switch and closed by actuation of said control relay, a second control relay for actuating said second electrically actuated means, a second normally closed timer relay in series with said second control relay for terminating operation thereof a predetermined time after actuation of said second control relay, a second manual switch biased to an open position for actuating said second control relay, a second switch mounted in parallel with said second manual switch and closed by actuation of said second control relay, and emergency means for opening the circuit to said control relays at any time.

References Cited in the le of this patent UNITED STATES PATENTS 719,669 Hoppe Feb. 3, 1903 2,758,836 Purdy Aug. 14, 1956 2,975,873 Beliveau et al Mar. 2l, 1961 

1. IN AN ENCLOSURE UTILIZED IN THE CONTROL OF AMBIENT ATMOSPHERIC CONDITIONS IMMEDIATELY SURROUNDING PROCESSING MACHINERY, A ROOF COVERING SAID MACHINERY, SIDE PANELS EXTENDING DOWNWARDLY FROM SAID ROOF AND TERMINATING SHORT OF THE FLOOR TO FORM AN APERTURE SUBSTANTIALLY COEXTENSIVE WITH SAID SIDE PANELS, GUIDE ROD SUPPORT MEANS MOUNTED ON SAID SIDE PANELS INSIDE SAID ENCLOSURE AND EXTENDING DOWNWARDLY FROM NEAR SAID ROOF TO THE LOWER EDGE OF SAID SIDE PANELS, GUIDE RODS MOUNTED ON EACH OF SAID SUPPORT MEANS, DOOR MEANS OPERABLE TO CLOSE SAID APERTURE, UPWARDLY EXTENDING ARMS ON SAID DOOR MEANS HAVING GUIDE BUSHINGS THEREON WHICH SLIDE ON SAID GUIDE RODS TO RESTRICT MOVEMENT OF SAID DOOR MEANS, A FLUID MOTOR OPERABLE TO MOVE SAID DOOR MEANS BETWEEN A LOWERED AND A RAISED POSITION, VALVE MEANS FOR CONTROLLING THE OPERATION OF SAID MOTOR, CONTROL RELAY MEANS, MANUALLY ACTUATED SWITCH MEANS BIASED TO AN OPEN POSITION AND OPERABLE WHEN CLOSED TO ACTUATE SAID CONTROL RELAY MEANS, A HYDRAULIC PUMP ACTUATED IN RESPONSE TO ACTUATION OF SAID CONTROL RELAY MEANS FOR GENERATING A PRESSURIZED FLUID, MEANS FOR POSITIONING SAID VALVE MEANS TO CONDUCT SAID PRESSURIZED FLUID TO SAID MOTOR IN RESPONSE TO ACTUATION OF SAID CONTROL RELAY MEANS TO EFFECT MOVEMENT OF SAID DOOR MEANS TOWARD EITHER OF SAID POSITIONS, A TIMER RELAY ACTUATED BY SAID CONTROL RELAY MEANS, AND A TIMER SWITCH MOUNTED IN A CIRCUIT IN SERIES WITH SAID MANUAL SWITCH MEANS AND ACTUATED BY SAID TIMER RELAY TO MAINTAIN A CIRCUIT TO SAID CONTROL RELAY MEANS WHEN SAID MANUAL SWITCH IN RELEASED, SAID TIMER RELAY BEING OPERABLE AFTER THE EXPIRATION OF A PREDETERMINED AMOUNT OF TIME TO OPEN SAID TIMER SWITCH TO INACTIVATE SAID CONTROL RELAY MEANS. 